Shaft sealing device



\ March 24, 1936. s. KARRER ET AL SHAFT SEALING DEVICE Filed Nov. 4, 1932 Patentgd Man. 24, 1936 UNITED 'STATES PATENT FFIC 2;os5072 SI-IAFT SEAIJNGEVICE Sebastian Kauer, Washington, D. 0., und Henry C. Mohlhenrich, Baltimore, Md., assig1nors I;o Consolidated Gas Elec'tric Light and Power I Company of Baltimore, Baltimore, Md., a. cor- -poration of Matyland Application November 4, 1932, SI 3l'ial N0. 641,262

12 Claims. 'Ihis Invention relates to shaft sealing devices,

end more particularly to devices cf I;his character which a'r ie used to seal the shaf.ts of pumps or compressors of refxigeration systems.

It is wellknewn that in rz'efrlgeration systems, such a s those (amploying sulphur dioxide as the circulatlng heat-ext'racting medium, corrosion of the parts will tke plane when air and water vapor leak 1nto the system, which corrosion in time will interfeie with proper operation of the system. Our investigations have shown that the types of seals or stuifing boxes provided for the shafts of the 'pumps end compressors cf most commercial household refrigerating systems will not prevent the infiltration of air and water vapor when the gas pressure within the compressor or pump Is Iess than the atmospheric pressure out-- side. We hav'e also. found that unless adequate provislons are made for ma.intaining a. liquid -filling between the relatively movable bearing erating fiuid from the system.

II: is therefore one of the objects oi the present invention to provide a. new and improved sea.ling device for the shaft of a compressor r pump which 'will not onlj efiectively prevent leakage of fiuids or vapor around seid sha.ft into and out of seid compressor or pump, but will also afiord an adequate supply of lubricant for the cooperating parts of said shaft and sea.l.v

Another object is to provide a. novel end efficient sealing device for the shaft of a refrigerator compressor or pump which can be quickly and easlly installed as an accessory in refrigerating systems already in use without requiring any reconstruction of the original mechanisin.

A further object is to provide a, pump or compressor shaft seal of simple construction which can be economically manufactured and readily installed to provide a highly eificient sea1 against the ingress and egress of gas and vapor with respect thereto.

Still another objecl; is toprovide a novel seal for compressoror pump slmfts in which a. quantity of sealing liquid can be stored and conserved for relatively long periods 0f time.

A still further object is to provide as a new article of manufacture a, unitary 011 reservoir and sealing device which is capable 013 being easily In- Sta.l1ed in the fleld as an accessory to a.nd to improve the efficiency of the variou.s sealing devlces with which the shafts oft refrigerator pumps or compressors are originally supplied.

These and other objects will appear more fully u'pon' a. consideration of I;he detalled description of the invention wh'ich folloWs. Although only one embodiment of the present invention Is desoribed and illustrated in I:he ac'companying drawing, it Is tobe expressly understood. tha.t this drawing is for the purpose 01' Illustration only end is not to be construed as a. definition of the scope of the invent ion reference being. had for this purpose to the appended claims.

In the drawlng, which constitutes a sectional view through the axis of the outer end 013 the shaft of a. compressor or pump showing' a shaft sealing device constituting one embo diment o1 the present inven'cion, I represents the shaft 01 a compressor or pump 013 a.ny desired type, such as the compressor of a household refrigeratingsys-4- tem, said shaft being journaled in a. suitable bearing 2 supported. in a portion of the compressor casing or housing 3. The outer end of shaft I is provided with an extenslon 4 Of reduced diameter Which projets outwardly beyond the end o1 compressor casing 3 and to the end of which 1S secured a. suitable drivring element, as a flywheel or driving pulley 5, the latter having a wedged fit with the tapered end of shaft extension 4 am]. being suitably secured thereon as by a-nut 6.

In Order 150 prevent leakage of the refrigerating fluid from within the compressor end infiltration of air and water vapor thereinto, a suiI;able sealing device is provided for the end of the compressor shaft. As shown, a sealing ring I of4amy suitable materlal is mounted. on the moVa.ble head 8 of a flexible bellows member 9 end is supported thereby in sealing engagementwith the shoulder II) formed at the junction of shaft extenslon 4 end the larger portion o1 shaft I. Bellows member 9 and its associated sealing ring I are housed in a suitable recess II formed. In the outer end of compressor casing 3, thefixecl head of the bellows havlng an enlarged outwardly extending flange I2 which is fixedly secured in proper position between the unter face of casing 3-and an annular retainlng plate I3 which is secured to said casing by a plurality of circumferentially spaced screws o1 bolts I4. If desired, a. sealing gasket I of any suitable material may be provided between flange I2 and the face of compressor casing 3. Sealing ring 1 is resiliently urged into sealing engagemeno wlth shoulder I0 by a. sultable coll spring I6 housed within bellows member 9 surrounding shafl; extensi0n 4 and exerting its thrust against the inner face of the movable head 8 of the bellows, the other end of said spring seating against the inner portion of annular retaining plate I3.

'I'he seal thus far described is a well known constructlon now in use on a large number 'of compressors and pumps of commerclal refrigerating systems. While this particular type 013 seal with stationary sealing bellows has been described in detail to show clearly the application of the present invention, lt will be obvious that the invention is equally applicable to other types o! seals, as for instance that in which the bellows ca.rrying the sealing member is attached to the 'shaft and rotates with lt.

In the type of seal described, escape of the refrigerating fluid can take place from within the compressor around shaft I into the recess I I, between the b'ea.ring surfaces of shoulder III and sealing ring I into the interior of bellows member 9 and out to the atmosphere through the opening in retaining plate I3 around shaft extension 4, while infiltration of air and water vapor froz'n the atmosphere into the interior of the compressor may take place in the opposite direction. In this usual type of seal espe-' cially when no 011 or other-lubricant is provided ior c.he bearlng surfaces o1 shoulder Ill a'nd sealing rlng I, the rotes of leakage and infiltration may beoome relatively high.

In order to prevent such leakage and infiltration, and also to adequately lubrlcate the bearing surfaces of the seal, the present invention includes a reservoir for a, sealing liquid, which is also preferablya lubricant and which reservoir is in communication with the sealing device. Sald reservoir may be installed as a unit in the field upon seals of the type just described or it may form a part of the seal as originally provided by the compressor manufacturer. -In the form shown, the reservoir comprises a casing I'I.

. 130 one end of which ls suitbly secured a, flexible wall er diaphragm I8 having a central opening therein which is slightly large1 than the diameter of shaft extension 4 the fiexibility of said wall or diaphragm being providecl in any suitable manner, here shown as by forming therein a. plurality of concentric circular corrugations I9, while the sealing means also inclucles means of any suitable construction for preventing leakage of 011 between said wall I8 and the .shaft 4, here shown as a sealing ring 20 of suitable material secured to the wall I8 around sald c entral opening. While casing I I may be of any desired shape, dependent upon the construction o1 the shaft seal 130 which the reservoir is applied, and said casing may be mounted on the platze I3 in a'ny suitable way, the embodiment illustrated is substantially cyllndrical with ibs interi0r diameter equal to or slightly larger than terior of casing I'I and the heacls of screws I4 'is obtalned when the reservoir is moved into place.

In installlng the combined lub'rlcating andsealy ing device in the field, lt ls necesary only to remove flywheel 5 from the end of shafi: extension 4, slide the reservoir and lts associated. sealing ging over the end 01 the shaft, and.then move casing I'I over the heads of screws I4 ami into engagemeni; with the outer face of annula.r retaining platze I3. An oil-tight gasket 2I is preierably inserted between plate I3 anal the end of casing I'I, and the joint formed between sald elements is covered with a, suitable liquid cement as indicated at 22. A suitable washer 23 and oil-proof gasket 24 am then placed upon shaft extension 4 and moved into engagement with sealing ring 20, and finally flywheel o1 driving pulley 5 is replaoed upon the shaft in engagement with gasket 24 110 comp lete the assembly. Wh'n thus assembled, the space enclosed by retaining plate I3, casing I'I, fiexible wall I8 and the sea1 comprising sealing ring 20 a.nd its associated elements cooperating with the shafl; or the flywheel 'o r driving pulley 5 constitutes a, liquid-tight reservoir which communicates with the interior 01 bellows member 9 through the opening in re-' taining plate I3 around shaft extension 4. This reservoir is also provided with a suitable filling member 25 through which oil 01 other sultable sealing liquid 26 is added until the entire seal,

including the interior of bellows member 9, is

completely full, as shown in the drawing, whereby not only is the bellows kept full of sa.id liquid but the liquid in the bellows is ma.intained under a head by the liquid in the reservoir. Hence leakage between the bearing surfaces between ring I and shoulder III is prevented by the liquid filling between said surfaces, while the volume of liquid in the reservoir is suflicient to keep the bellows full and prevent the destruction of the sealing film, notwithstanding the reversals in, pressure which occur in the relative values of shapes'of the elements with which they will be installed or the clearance between the lnner face 01'" flywheel or driving pulley 5 and the outer face o1 retaining plate I3. Also in some refrlgerating unlts the compressor er pump shaft is directly connected with a motor so thatno driving pulley or flywheel is used, but it will be understood that the present inventlon may still be embodied in such a. construction by providopen I;o the atmosphere, so that any refr igerating fluid which ma.y escape from the compressor pa.st the compressor seal during the filme when the refrigerator is defrosting, o1 when for other reasons the compressor i s not operatlng, will escape directly I;o the atmosphere, and will not build up a. high pressure on or eject the seallng liquid. Thus,'the pressure tending to force the sealing liquid past the seal between bearing ring 20 a.nd washer 23 is only the hydrostatic pres-.

sure due to the height of the liquid 26 within the reservoir. 'I'he pressure on the liquid 26 within the reservoir thus belng very small, only a slight, pressure of bizaring ring'20 against washer 23 is necessary to prevent leakage of the liquid resiliency is not suflicient to provide the presfal; this point. 'I'his outward pressure is normally obtained by the resiliency of flexible wall or diaphragm I8, although in the eveni; that thissure necessary 110 maintain a liqid-tight seal between bearing ring 20 and washer 23, a. suitable coil spring 21 may be provided inside of the reservoir exerting its thrusi; against the inner face of flexible wall I8 with its opposite end se'ating against the outer surface of annular retaining plate I3.

While the invention has thus far been described as adapted for embodiment in an accessory unit; to be applied 130 compressor or pump shafts a1- ready in service and equipped with a dry seal of well known construction, it is apparent that it may also be embodied in complete sealing devices to be applied at the time of original assembly of the compressors or pumps. In such event, it would be desirable to modify the construction of the reservoirsomewhat, as for example, by decreasing the diameter of cylindrical casing I'l to a. dimension less than the diameter of the -circle passing through the inner edges of the heads 0f screws I4 and providing said casing with an autwardly extending flange whereby the reservoir could be securely fastened to retaining plate I3 and the compressor casing 3 by screws I4. Such a inodified construction would not be desirable for an accessory to be instal1ed in the field since it would necessitate the removal cf screws I4 fsr its y installation and thus afford opportunity for leakage through the joints cf the seal.

- There is thus provided by the present invention a'new and improved sealing device which is paralready installed ticularly weil adapted for use on the shafts of which can be quicklyand easily installed on a compressor or pump already in service so a.s to greatly increase the efficiency cf the existing seal, said installation being possible without impairing the existing seal 'or necessitating removal of the refrigerating fluid from the system. It will be obvious, however, that the invention is not iimited to the construction shown in the drawing, but is capable of a variety of mechanical embodiments.

For example, any suitable means may be employad for securing the reservoir in its proper position instead of the specific arrangement shgwn, while other forms of resilient wall may be substit-uterl. for the corrugated diaphragm described and illustrated. Also, in some installations a ufficiently tight seal can be obtained between seal-' ing ring 20 and the shaft or the hub of flywheel or driving pulley 5 and washer 23 and gasket 24 may be omitted. Various other changes, which will now appear to those skilled in the art, may be made in the form, details of construction and arrangement of the parts without departing irom the spirit cf the invention, and reference will therefore be had to the appended claims for a definition of the limits cf the invention.

What is claimed is:

1. An accessory to be applied to the shaft o! a compressor or pump between the flywheel er driving pulley thereof and an existing seal of the type embodying a sealing ringengaging a shoulder on the shaft and mounted on one end of a flexible bellows member the other end cf which is clamped to the compressor or pump casing b v a retaining plate secured to said casing, comprising a reservoir having a cylindrical casing closed at one endby an annular end wa1l, the opening in said Wall being larger than said shaft whereby the reservoir may be placed upon said shaft with its open end secured to said retaining platze and the inte rior thereof communicating with the interior of said bellows member means through which said reseivoi1 and the communicating beilows member may be filled with a sealing liquid, and sealing means carried by said end wall and adapted to cooperate with said flywheel or driving plley to form a fluid-tight joint for preventing leakage of said sealing liquid from the reservoir.

2. A sealing device for the shaft of a compressqr or pump of the type having a fiywheel er driving pulley secured to the end 015 the shaft which extends outside of the compressor or pump casing,

comprising a shoulder formed on said shaft, a

sealing ring in engagement with said shoulder,

a. bellows member surrounding said shaft on one end cf which said sealing ring is mounted, a fiange secured to the oth-er end of said bellows member, an annular retaining platze secured to the pump er compressor casing, a substantially cylindrical casing surrounding said shaft between said retaining plate and the flywheel or driving pulley with its inner end secured to said plate, an annular end wa.ll closing the outer end o1 said casing a.round said shaft, said casing, retaining plate and end wa1l forming a reservoirior a, sealing liquid the interior of which is in'commumcation with the interior 013 said bellows member, means through which said sealing liquid may be suppl ied to said reservoir, and a. sealing member carried by said end wall and c0operating with the flywheel or driving pulley to form a fiuid-tight joint therebetween for preventing leakage of said sealing liquid from the reservoir.

3. An accessory adapted to be applied to the shaft of a compressor or pump and to cooperate with an existing sealing device including a sealing ring engaging a shoulder on the s haft and mounted on one end of a bellows member with the other end ofsaid bellows member making a fluid-tight joint with thecasing of the compressor or pump, said accessory comprising a reservoir adapted to be detachably mounted about said shaft laterally with respect to theend of said bellows member and without modification of the existing seal with the interior thereof in free communica.tion with the end of the chamber within said bellows member whereby said chamber may be maintained full of said liquid under a head of liquid existing in said reservoir, means through which said reservoir and the c'ommunicating bellows member may be filled with a sealing liquid, and sealing means carried by said reservoir and adapted to form a iiuid-tight joint for preventing leakage of saidsealing liquid from said resy freely in communication withthe chamber of said bellows, said reservoir adapted 120 contain a sealing-liquid and to maintain said chamber fu1l of said sealing liquid under a head bf liquid existing in said reservoir, means for securing said reservoir to said chamber laterally with respect to the endthereof, and sealing means carried by said reservoir for preventing leakage 01 the sealing liquid therefrom along the shaft.

5. In asealing device i'or the shaft 015 a. compressor or pump, in combination with the shatt and a. seal for said shaft including a bellows surrounding the shaft and having a sealing ring engaging an opposed surface to provide relatively rotatable sealing surfaces, means for maintaining said sealing surfaces under a head 01 sealing liquid comprising a reservoir closed at one end by a resilient end wall apertured to receive the shaft and adapted surround said shaft with the interior thereof freely in communication with the chamber of said bellows, said reservoir adapted to contain a sealing liquidand to maintain said chamber full of said sealing liquid under a head 01. liquid existing in said reservoir, means for securing said reservoir to said chamber laterally with respect to the end thereof, and sealing means carried by' said resilient end wall for preventing leakage of said sealing liquid from said opening in the end wall of the reservoir.

.6. In a sealing device for the shaft of a com pressor or pump, in combination with the shaft and a seal for said shafi: including a bellows surrounding the shaft and having a sealing ring engaging an opposed surf ace to provide relatively rotatable sealing surfaces, means for maintaining said sealing surfaces under a head of sealing liquid compris ing a reservoir having a flexible end wall apertured toreceive the shaft andadapted to surrbund said shafl: with the interior thereof freely in communication with the chamber of said bellows, said reservoir adapted to contain a seal- Ing liquid and to maintain said chamber full of said sealing liquid under a head cf liquid existing in said reservoir, means for securing said reservoir 1:0 s'aid chamber laterally with respeci; to the end thereoi', sealing means carried by said flexible end Wall, and resilient means within said reservoir 1'01- urging said sealing means into sealing engagexnent with ineans rotating with said shaft to prevent leakage cf the sealing liquid from said opening in the end wal1 of the reservoir.

7. In a sealing device for the shaft; of a compressor or pump, an expansible and collapsible chamber surrounding said shaft and having a sealing ring in engagement with an opposed surface to provide relatively rotatable sealing surfaces, and means for supplying a. sealing liquid to said sealing surfaces including a. reservoir mountd laterally with respect to the end of said chamber and having free communication through the end of said chamber with the interior thereof, said reservoir adapted to contain a sealing liquid and having a vertical radial dimension materially in excess of the radial dimension of said chamber, whereby said reservoir is adapted to maintain said chamber full of sealing liquid under a head of liquid existing in said reservoir, and sealing means carried by said reservoir and actixig independently of said sealing ring prevent leakage of the se'aling liquid therefrom along the shaft.

8. In a sealing device for the shaft 013 a compressor or pump, a resiliently actuated expansible and collapsible charnber surrounding said shaft and having a sealing ring in engagement with an opposed surfaceto proVide relatively rotatable sealing surfaces, and means for supplying a. sealing liquid to said sealing surfaces including a reservoir mounted laterally with re spect to the end of said chamber and having free Communication through the end of said chamber with ighe interior thereof said reservoir adapt ed to contain a sealing liquid and having a vertical radial dimension materially in excess of the radialdimension 015 said chamber, whereby said reservoir is adapted to maintain said chamber full of sealing liquid under ahead of liquid existing in said reservoir, said reservoir including a resiliently actuated end all and sealing means carried thereby and aCting independently o! said resiliently actuatedchamber, to prevent leakage oi' the. sealing liquid from said reservoir along said shaft.

9. In a sealing device ior the shaft o1 a. compressor or pump, an expansible and collapsible chamber surrounding said shaft and having a 'sealing ring resiliently urged lnto engagement with an opposed surface provide relatively rotatable sealing surfaces and form a gas-tight seal, and means for supplying a. sealing liquid tosaid sealing surfaces including a reservoir mounted laterally with respect to the end of said chamber and having free communication through the end of said chamber with the interior thereof, said reservoir adapted to contain a sealing liquid and having a vertical radial dimension materially in excess of the radial dimension of said chamber,

whereby said reservoir is adapted to maintain said chamber full of sealing liquid under a head 013 liquid existing in said reservoir, said reservoir ind:luding a flexible end wall, sealing means carried thereby, and resilient means in said reservoir cooperating with' said sealing means and acting independently oi said resiliently urged sealing-. ring to urge said sealing means into contact with means rotating with said shaft and f01m a liquidtighi: seal.

10. In a sealing device for the shaft of a compressor 0r pump, a. bellows surrounding the shaft and having a sealing ring engaging an opposed said chamber laterally with respect to the end thereof, sealing means carried by said reservoir fcr preventing leakage cf the sealing liquid therefrom along the shaft, and means for venting the interior cf the reservoir to the atmosphere whereby .any gas which may leak from the compressor or pump through said chamber and into said reservoir ma7 pass to the atmosphere.

11. In a sealing device for the shaft 015 a compressor or pump, in combination with the shaftand a seal for said shaft including a bellows surrounding the shaft and having a. sealing ring engaging an opposed surface to provide relatively rotatable sealin'g surfaces, means for mintaining said sealing surfaces under a head of sealing liquid comprising a, reservoir closed 'at one end by an end wall aperbured to receive the shaft and adapted to surround said shaft with the interior thereof freely in communication with the chamber of said bellows, said reservoir adsipted to contain a of said sealing liquid under a h ead of liquid exlsting in said reservoir, means fordetachably securing said reservoir to said chamber laterally with respect to the end there0f, and sealing means carsealing liquid and to maintain said chamber full ried by said end wall for preventing leakage 01: said sealing liquid from said opening in the end Wall of the reservoir.

12. In a, sealing device for the shaft of a compressor or pump, an expansible and collapsible chamber surrounding said shaft and having a sealing ring in engagement with an opposed surface to provide relatively rotatable sealing surfaces, and means for supplying a sealing liquid to said sealing surfaces including a, reservoir mounted laterally with respect to the end of said chamber und having free communication through the end of said chamber With the interior thereof, said. reservoir adapted to contain a. sealing liquid und. having a, vertical radial dimension materially in excess of the radial dimension of said chamber, whereby sa.id reservoir is adapted to maintain said chamber ful1 of sealing liquid under a head 0f liquid existing in said reservoir.

SEBASTIAN KARRER. 

